The use of bituminous compositions, notably of cross-linked bitumen/polymer compositions, is known, as coatings of diverse surfaces and, in particular, as road surfacings, provided that these compositions as a combination have a certain number of characteristics, notably mechanical characteristics. In order to maintain and/or improve the characteristics and notably the mechanical properties of a conventional bitumen, bituminous compositions have been used for a long time in which the bitumen (formed with one or several types of bitumens) is mixed with one or more functional polymers, notably styrene and butadiene elastomers, these elastomers being optionally chemically cross-linked in situ, optionally with a coupling or cross-linking agent, for example sulfur or at least one of its precursors.
Optimized mechanical characteristics are notably crucial for road surfacing applications. Beyond mechanical properties, for bitumens, their sensitivity to certain chemical agents should be taken into account. These aggressive chemical agents may for example be hydrocarbon solvents, in particular petroleum solvents such as kerosines, gasoils and/or gasolines or even products, in particular fluids, used for deicing and/or defrosting and/or removing snow from aircraft and taxiing areas. These fluids are for example aqueous potassium, sodium, magnesium and/or calcium saline solutions and/or compositions based on ethylene glycol and/or based on propylene glycol.
The aggressive effect of such chemical agents cumulates with the constraints of intense traffic, notably of heavy vehicles, and of bad weather, which has the detrimental effect of increasing rapid degradation of the roadways, in particular aeronautical roadways. This sensitivity of bitumens to aggressive chemical agents, to chemical aggressions is more specifically a nuisance for bitumens for example making up tarmacs and airport strip surfacings, which are made in bituminous coatings (bitumen/aggregates aggregate). Indeed, these tarmacs and airport surfacings are frequently soiled with kerosine drippings, during the filling of aircraft tanks, by leaks or other accidental spills of petroleum products. In addition, they are also exposed to various fluids used in cold weather for removing ice, frost and/or snow on aircraft and on the strips.
Surfacings of filling stations as well as of industrial premises of hydrocarbon depots may also be subject to this same problem of resistance of bituminous coatings to aggressive chemical agents which are hydrocarbon solvents and/or deicing/defrosting/snow removal fluids. Conventional roadways are naturally also exposed to this type of chemical aggressions.
In order to attempt to find a remedy to this, incorporation of various additives into the bitumens was proposed. Thus, patent EP1311619 describes the use of waxes in bitumens in order to improve their resistance to hydrocarbons. The waxes are in particular synthetic waxes stemming from the Fischer Tropsch synthesis process.
The applicant corporation proposed in patent application EP1756228 the incorporation to bitumen of polyamines with fatty chains, preferably polyamines with fatty chains obtained by reacting polyalkylene polyamines with fat chains of general formula R—NH—(CH2—CH2—CH2—NH)n—H wherein R represents a linear, saturated and/or unsaturated hydrocarbon chain, with 8 to 22 carbon atoms, n is an integer from 1 to 5, with formic acid in order to improve their resistance to chemical aggressions and in particular to hydrocarbons. These compositions are excluded from the present invention.
The applicant corporation also proposed in patent EP1572807 the incorporation to bitumen of functionalized olefin polymers selected from random terpolymers of ethylene, of alkyl acrylate or methacrylate and glycidyl acrylate or methacrylate, in order to improve resistance to petroleum solvents. Patent EP0900253 describes the use of copolymers of ethylene and of vinyl acetate in bitumen for improving resistance to kerosine.